iMac crashing a lot

sydneyk.andrews_48ae5ebd06

Is there anyone NOT having a ton of crashes with the following machine:

Daz 4.9 Pro

iMac (21.5-inch, Late 2015) OS: 10.11.6 (15G31)

2.8 GHz Intel Core i5

8 GB 1867 MHz DDR3

Intel Iris Pro Graphics 6200 1536 MB

Mine crashes or hangs and I have to force quit alot. Sometimes during rendering, sometimes just simply changing a parameter. but either way, crash crash! ACK!